Entwined in two sheets of purple polyester, Moira Lee dangled gracefully from a 19-foot-high aluminum frame and spun her magic on a crowd gathered at Baltimore's Harborplace on Saturday. The audience cringed as she appeared to fall, only to catch herself inches from the ground. A few yelled "ouch" when she held a midair split for long seconds, and cheered as the petite woman in a mossy green leotard contorted into impossible shapes.

"Not many people can do that," said Kelsey Thomson, 16, part of the crowd of onlookers and a volleyball player from Dallas who risked whiplash trying to follow Lee's aerial maneuvers from a concrete seat in the amphitheater by the Inner Harbor.

Lee was one of several acts auditioning on Saturday to become part of the Harborplace street performer program. She was competing against magicians, musicians and dancers for a chance to join a select group of artists. With 30 street performers, many of them veterans, already on the schedule, the judges overseeing the tryouts would be adding only a few talented crowd-pleasers.

"The annual auditions help us see who the crowd might sit and watch," said Carmel Gambacorta, Harborplace's senior marketing manager. "Street performers define Harborplace and give visitors something to talk about and remember. It is really interesting to see what most people will stop and watch."

"We look for interaction with the crowd," said Debbie Zink, volunteer coordinator for the Baltimore Office of Promotions and Arts and one of three audition judges. "We want to see how the crowd receives the performer and how the performer draws them in."

Kelsey and her teammates on the Skyline Junior Volleyball Team were at Harborplace during a break in a competition at the Convention Center. The team rated Lee among the best, along with a dance trio dubbed the Regulators.

That group "really got the audience involved," said Katie Byland of Dallas.

Audience reaction can help a performer secure a spot on the seasoned troupe that entertains for tips at Harborplace.

The audience grew as many of those walking along the waterfront stopped to watch, particularly during Lee's act. She started by dancing on stilts and ended by balancing upside-down on a stool and manipulating a puppet with her left foot.

"Kids, don't try this at home," said Mike Rosman, emcee and a Harborplace street performer for more than 25 years. Judges won't be releasing their picks for several days.

Another requirement for performers, Gambacorta said, is adaptability.

"You have to prepare, when you are performing outside," she said. "You have to have Plan B, when your sound equipment fails."

As the weather warms, Gambacorta said, she has received calls from other cities trying to emulate the street performances that date to Harborplace's opening in 1980.

"Street performing is one of the first forms of free expression and has gone on forever," said Talbolt Johnson, a dancer with the Regulators. "This waterfront is the perfect venue for it."

Lee said the art form allows her to perform on her own terms and "bring theater from indoors out into the world."